Circular knitting machine for producing elastic fabrics



E. J. TOWERS Jan. 9, 1940.

CIRCULAR KNITT I NG MACHINE FOR PRODUCING ELASTIC FABRICS Filed April 5,'1939 3 Sheets-Sheet 1 Jan. 9, 1940. E. J. TOWERS CIRCULAR KNITTINGMACHINE FOR PRODUCING ELASTIC FABRICS Filed April 3. 1939' A 3Sheets-Sheet 2 Jan. 9, 1940. E. J. TOWERS CIRCULAR KNITTING MACHINE FORPRODUCING ELASTIC FABRICS Filed April 3, 1939 3 Sheets-Sheet 3 PatentedJan. 9, 1940 UNITED STATE omcoma KNITTING MACHINE Fon raonocme msrrcFABRICS Ernest John Towers, Ruddington, England, as-

signor to George Blackburn and Sons Limited,

Nottingham, England Application April 3, 1939, Serial No. 265,798 InGreat Britain February 15, 1938 6 Claims.

This invention relates to improvements in circular knitting machines forproducing knitted elastic fabrics, and its object is to produce on suchmachines, a. non-ribbed fabric in which straight elastic weft threadsare introduced therein in a manner which is somewhat similar to thatadopted in hand frames or straight bar knitting machines, and therebyproducing elastic fabrics very similar to those made on a hand frame.

- In order to produce an elastic fabric according to this invention, theneedle cylinder of a circular knitting machine is fitted with latchneedles, the whole or part of which may be con- 5 structed or associatedwith means whereby the loops can be readily removed therefrom by meansof transfer instruments disposed in the dial. These transfer instrumentsare equal in number to and cooperate with the transfer needles in theneedle cylinder, and the manipulations of the loops in a course whichare necessary to embody an elastic yarn in the knitted fabric as it isproduced, are effected by the needles and transfer instruments atdifferent points in the circumference of the machine, where the cams areadapted to actuate the said needles and transfer instruments in therequired manner.

In one order of working, the ground thread is first taken on both thecylinder needles and the transfer instruments, the elastic weft threadis inserted between the loops disposed on the needles and those disposedon the transfer instruments, and then the loops on the latter aretransferred on to the cylinder needles and the 35 weft thread secured byknitting a course on the needles.

In an alternative order of working, the ground thread is taken on theneedles, a portion of the loops are taken from the needles on to thetransfer instruments, the elastic weft thread is inserted between thetwo sets of loops, and then the removed loops are returned back to thecylinder needles again before knitting the next course. In both casesthe several operations entailed are effected at different points in thecircumference of the machine.

The structure of the elastic fabric produced as described is notprecisely the same as that produced on a. hand frame or on a straightbar machine fitted with bearded needles, as this is not possible for thefollowing reason. In a hand frame for instance the courses are drawnon-the needles by the sinkers, and the weft thread is inserted betweenthe divided loops in the course before it is knitted. In a circularknitting machine with latch needles, the ground thread is taken by theneedles and simultaneously knitted, and the division of the loops inorder to embody a weft thread in a course, must take place after insteadof before the course is knitted.

The invention will now be more particularly described with reference tothe accompanying drawings, in which Figs. 1 to 8 inclusive are diagramsillustrating the series of operations which are necessaryin 10 order toembody a weft thread in a knitted fabric in the process of manufactureaccording to our invention.

Fig. 9 is a development of the cams in the cam case which are adapted toactuate the needles as is required to effect the different operationsshown .in Figs. '1 to 8.

Figs. 10 to 1'7 inclusive are diagrams showing an alternative order ofworking which is adapted to embody a weft thread in a knitted fabric 26according to our invention.

Fig. 18 is a development of the cams for actuating the needles in themanner described and shown in Figs. 10 to 17.

Fig. 19 is a view showing part of the upper end of the needle cylinder.

Fig. 20 is a plan of the dial cams for actuating the transferinstruments as described and shown in Figs. 1 to 8.

Figs. 21 and 22 are front and side views of one form of transferneedle.-

Figs. 23 and 24 are front and side views of another form of transferneedle.-

Like letters indicate like parts throughout the drawings.

In carrying out this invention, transfer needles of any well knownconstruction may be employed, for example the needles B shown in Figs.21 and 22 each of which is formed with a crank B to expand the loops maybe adopted, but the objec- 4 tion to this'type of needle is that owingto the space takenup by the crank B, the needle tricks or gates have tobe omitted from the upper end of. the needle cylinder f and theupperends of the needles are thereforef 'unsupported.

In order to overcome this defect, straight needles A shown in Figs. 23andfZl a re employed, and a jack A with a crank A for expanding theloops, is disposed at the side of and in the same trick as each transferneedle. The crank 5 A on each jack A can in this case be located outsidethe tricks or gates in which the needles are disposed, and the upper endof the needles A are not only as shown in Fig. 19 efiiciently supportedin gates which extend up to the top 5 of the needle cylinder C, but-thelatter can as shown'in Fig. 19 be formed with extensions C which holdthe upper ends of the jacks A close up to their needles A. The jacks Ait will be understood are actuated by the same cams as the needles A.

The transfer instruments D in the dial of the machine are of the usualcranked type and two of them placed together as shown in Figs. 10 to1'7, form an ordinary pelerine instrument, which is usually employed totake a loop off one needle and place it on two.

In the order of working shown in Figs. 1 to 9 inclusive, a full set oftransfer needles A with a transfer jack A associated with each, ispreferably disposed in the needle cylinder, and elastic weft threads Gare embodied at the required intervals in courses in the fabric in thefollowing manner. A ground thread F is fed to the needles A-atone pointin the circumference of the machine and is taken by both the needles. Aand transfer instruments D as shown at Fi 1. At a second point in thecircumference of the machine an elastic weft thread G is introducedbetween the loops on the needles A and those on the instruments D asshown in Fig. 2. At a third point the loops on the instruments D aretransferred to the needles A, and this is efiected by projecting theinstruments D until the loops thereon are extended, and then raising theneedles A up through the loops and subsequent- 1y retracting theinstruments D so as to leave did the loops on the needles A. The loopswill now be all on the needles A, and the elastic weft thread G will beembodied in the course as shown in Fig. 4 when the next course isknitted.

Another weft thread can now be inserted by repeating the operationsdescribed, but if one or more ordinary courses are to be knitted betweeneach weft thread course, extra yarn feeders and knitting cams areprovided, and openwork ornamental effects can be produced in thesecourses, by transferring loops by means of the transfer needles A andinstruments D already provided for introducing the elastic weft thread Ginto the fabric.

Intransferring loops, the needles A on which the l'oops which are to betransferred are disposed, are first raised until the loops on theneedies are expanded by the cranked portions A on the jacks A and thetransfer instruments D are projected until their outer ends are disposedbetween the raised needles A and their associated jacks A as shown inFig. 5, and theneedles A are then lowered leaving. the loops on thetransfer in struments D as shown in Fig. 6.

The loops are then ret'lirned but not to the same but to adjacentneedles so as to form eyelet holes, and this is eflected by projectingthe transfer instruments Duntil the loops are expanded by their crankedends, then raising the needles A up through the expanded loops as shownin Fig. 7, and finally retractin the instruments D, leaving the loopsdisposed n a new order on the needles A as shown in Fig. 8. The transferinstruments D will not return the loops to the same needles from whichthey were removed, but to needles on the right or left ofthelattenaccording to the position of the cranks on the transfer instruments D.

In the development of the needle cams shown in Fig. 9, the cams at thefirst point for actuating the needles A, are adapted to draw a course onthe needles A and transfer instruments D as described and shown in Fig.l. The cams at the areaeoe second point are adapted to retain theneedles A as is required when the weft thread is being fedin asdescribed and shown in Fig. 2. The cams disposed at the third point areadapted to raisev the needles A so as to take the loops from theinstruments D as described and shown in Figs. 3 and. 4. The cams at thefourth point are adapted to actuate the needles A so as to knit anordinary course.

At the fifth point pattern or jacquard mechanism is provided to raiseselected needles A, so that loops can be removed therefrom by thetransfer instruments D as described and shown in Figs. 5 and 6 The camsat the sixth point are adapted to raise the needles A high enough totake the loops from the instruments D as described and shown in Figs. '7and 8.

In the alternative order of working which is shown in Figs. 10 to 1'7inclusive, the needle cylinder 0 is fitted with ordinary needles B inalternate tricks or gates, and with transfer needles A associated withloop expanding jacks A in the remaining tricks or gates, and the dial isfitted with loop transfer instruments H to work in conjunction withthetransfer needles A in the needle cylinder.

The transfer instruments H in this case are ordinary pelerineinstruments which are generally used for placing one loop on twoneedles, and thus forming eyelet holes in the work. The advantage ofusing these instruments is that by using them as hereinafter described,a loop removed from one needle A can be replaced on the same or on anadjacent needle, or it can be replaced on two needles and form a largereyelet hole when required.

In this case the ground thread F is fed to the needles A and B as shownin Fig. 10, and then the needles A are raised and the loops removedtherefrom by the transfer instruments H as shown in Figs. 11 and 1 2.The elastic weft thread G is now inserted between the loops on theneedles B and instruments H as shown in Fig. 13, after which the loopsare returned from the instruments H to the needles A again.

This is eflected by projecting the transfer instruments H so that theyexpand the loops and then raising one needle A through each of theexpanded loops as shown in Fig. 14. As shown in Fig. 15 the loops havebeen returned to the same needles from which they were removed, while asshown in Fig. 16, the loops have been returned to different needles.

The transfer instruments H are wide'enough to place a loop on twoneedles A as shown in Fig. 17,-

and will do this if two needles A are raised, or it will place the loopon either of the needles which are raised.

In the development of the cams (see Fig. 18) for actuating the needlesin the manner described and shown in the diagrams Figs. 10 to 17, thecams at the first point are adapted to actuate the needles A and B as isrequired to draw a course on the needles as described and shown in Fig.10. At the second point the cams are adapted to actuate the transferneedles A in order to transfer the loops thereon to the instruments H asshown in Figs. 11 and 12, and for this purpose the said needles havelonger butts than the ordinary needles B and these longer butts areengaged by the clearing cam J. The elastic weft thread G is introducedat the third point where the needles A and transfer instruments D areholding the loops as shown in Fig. 13, and at the fourth point theneedle cams are adapted to actuate the needles as "be raised to ,deliverthe loops at the second point and the needles M will be raised toreceive the loops at the fourth point. The cam P is in this casedisposed in the lower dotted position.

The cams for actuatingthe transfer instruments D as described and shownin Figs. 1 to 8 are shown in Fig. audit will be seen that the cams atthe first point area apted to position the instruments D so as to takethe loop of ground thread as shown in Fig.1.

The elastic weft thread 6 is inserted at thesecond point.

At the third point the cams are adapted to operatethe instruments D asis required to transfer the loops from the said instruments to theneedles, as shown in Figs. 3 and '4.

At the fourth point the cams are adapted to withdraw the instruments Dfrom action while the next ordinary course is being knitted. At thefifth point the cams are adapted to project the instruments D far enoughto take the loops from selected needles A which are raised as shown inFig. 5 and at the sixth point the cams are adapted to operate the jacksso that they return the loops to the needles A as shown in Figs. '7 and8.

When two or more courses are knitted between the weft thread courses,tuck stitches may be formed on certain selected needles and when makingopenwork effects by transferring loops, tuck stitches may be made on theprevious course on the needles from which the loops are trans-- 'thefollowing operations at difierent' points in the circumference of themachine, divide the ground' thread loops between the needles andtransfer instruments at one point so that an elastic weft thread can beintroduced between them, restore the loops tothe needles at anotherpoint, and knit an ordinary course on the needles at an other point,substantially as described.

2. In a circular knitting machine, the combination of a needle cylinder,needles therein with loop transfer means, a cam case associated with thecylinder, a dial, loop transfer instruments in the dial, a cam capassociated with the dial, and

cams in the cam case and dial cap which are adapted to actuate theneedles and transfer instrument and effect the following operations atdifferent points in the circumference of the machine, that is, take theground thread loops on the needles and transfer instruments at one pointso that an elastic weft thread can be introduced between them, transferthe loops from the transfer instruments to the needles at another point,and knit an ordinary course on the needles at another point,substantially as described.

3. In a circular knitting machine the combination of a needle cylinder,needles therein with loop transfer means, a cam case associated with ethe needle cylinder, a dial, loop transfer instruments therein, a earn'cap associated with the dial; and cams in the cam case and cam dial capwhich are adapted to actuate the needles and transfer instruments andeffect the following operations at different points in the circumferenceof the machine, that is, take a course of the ground thread on theneedles at one point, transfer alternate loops from the needles to theinstruments at another point so that an elastic weft" thread can beintroduced between them, return the loops to the needles at anotherpoint, and

knit an ordinary course on the needles at anothe point, substantially asdescribed.

4. In a circular knitting machine, the combination of a needle cylinder,needles therein with -1oop transfer means, a cam case associated withthe cylinder, a dial, loop transfer instrumentsin the. dial, a cam capassociated with the dial, and cams in the .camcase and dial cam, capwhich are adapted to actuate the needle and transfer instruments andeffect the following operations at different points in the circumferenceof the machine, that is, take the ground thread loops on the needles andtransfer instruments at one point so that an elastic weft thread can beintroduced between them, transfer the loops from the transferinstruments to the needles at another point, knit an ordinary course onthe needles at' another point, transfer selected loops of this coursefrom one needle to another at another point and subsequently knit aplain course at a following point, substantially as described.

5. In a circular knitting machine, the combination of a needle cylinder,needles therein with loop transfer means, extensions on the needlecylinder for closing the loop transfer means, a cam case associated withthe needle cylinder, a dial, loop transfer instruments therein,a cam capassociatedwith the dial, and cams in the cam case and dial cam cap whichare adapted to actuate-the needles and transfer instruments and effectthe following operations at different. points in the .circumference ofthe machine, that is, take a course of the ground thread on the needlesat one point, transfer alternate loops from the needles to-theinstruments at another point so that an elastic weft thread can beintroduced between them, return the loops to the needles at anotherpoint, and knit an ordinary course on the needles at another point,substantially as described.

6. In a circular knitting machine, the combination of a needle cylinder,needles therein with 1 loop transfer means, a cam case associated withthe cylinder, a dial, loop'transfer instruments in the dial "comprisedof two blades both of which are cranked, a cam cap associated with thedial, and cams in the cam case and dial cap which are adapted toactuate'the needles and transfer instruments and effect the fellowingoperations at different points'in the circumference of the machine, thatis, take a course of the ground thread on the needles at one point,transfer. al-

ternate loops from the needles to the transfer instruments at anotherpoint so that an elastic weft thread can be introduced between them,

- transfer the loops from the transfer instruments

